We have designed the PURAIN Rainwater filter, sometimes known as the hydraulic jump filter, for roof areas ranging from 60m² to more than 6000m².
This filter automatically cleans itself by means of the hydraulic jump. The design model for PURAIN Rainwater filters comes from nature: At almost every course in a stream, you can see how the hydraulic jump functions. The water flows over one of the stones, smooth and rounded by the action of the water over time. The water flow is substantially changed by the height drop, from a sub-critical to a super- critical flow. At the bottom of the dip, the waterflow changes again to a subcritical flow in a process now commonly known as hydraulic jump. This resulting increase in water power is similar to a strong eddy and any impurities are then forced over the next level and washed away downstream.
The following types of PURAIN Rainwater filters are designed for a variety of needs from domestic to industrial:
PURAIN PR-100:
PURAIN Rainwater filter for a single family dwelling: including a non-return valve, protection against small animals entering the tank and skimmer overflow
PURAIN PR-100 o.R
PURAIN Rainwater filter for a single family dwelling: including a skimmer overflow
PURAIN PR-150 to PR-400:
PURAIN Rainwater filters for industrial, public or commercial buildings. Non-return valve, protection for small animals and skimmer overflow must be provided on-site.
